Electrical Transport Dissipation Effects in Epitaxial Y1ba2cu3o7.X Thin Films

Abstract

AbstractThe electrical transport properties of a series of Y1Ba2Cu307.x thin films deposited onto single crystal substrates by thermal coevaporation and laser ablation were investigated. For fully epitaxial, c‐oriented films on (001) substrate surfaces, the critical current density Jc showed large high‐field enhancements for the film aligned with H parallel to the copper‐oxygen planes. With H||c, a precipitous decay of Jc with increasing field is described by thermally activated flux motion. Films on (110) SrTiO3 substrates were comprised of finely‐divided arrays of grains having [110], and <103>‐type orientations, and exhibited granular behavior. For these “triaxial” films, the transport dissipation was also thermally activated but with much smaller energy barriers.